Extruder head for sealing containers

ABSTRACT

A carton having tubularly arranged walls and at least one end closure including closure flaps connected said walls and secured in face contact is sealed along the edges of the closure flaps by an extruder head having right angular faces designed to extend along a surface of the closure flaps and the adjoining carton wall. the extruder head includes an extrusion slot at the juncture of said faces extruded.

June 4, 1974 R, s I ETAL 3,814,650

EXTRUDER HEAD FOR SEALING CONTAINERS Filed Dec. 25, 1971 2 Sheets-Sheet l I I l i i if i fi Zfi C\Z7 5 3 5 A 5; PEPEWH 9B 22 I A '7/v' O 31 INVENTOR RAYMOND 5. 0/0 6 LOREN J. lfL/TZKE 40 BY F/G. 4 55 52 ATTORNEY June 4, 1974 R. D|K ETAL 3,814,650

EXTRUDER HEAD FOR SEALING CONTAINERS Filed Dec. 25, 1971 2 Sheets-Sheet 2 INVENTOR 33 RAYMOND S. DICK -4 Lona/v J KL/Tzm:

may] 4 BY'QAMWDMM- 5 #TORNEY United States Patent Edina, Miun., assignors to Hoerner Waldorf Corporation, Ramsey, Minn.

Filed Dec. 23, 1971, Ser. No. 211,303

, Int. Cl. B31!) 1 62 US. Cl. 156-500 5 Claims ABSTRACT OF THE DISCLOSURE A carton having tubularly arranged walls and at least one end closure including closure flaps connected said walls and secured in face contact is sealed along the edges of the closure flaps by an extruder head having right angular faces designed to extend along a surface of the closure flaps and the adjoining carton wall. The extruder head includes an an extrusion slot at the juncture of said faces extruded.

This invention relates to an improvement in Sealing Cartons and deals particularly with means of applying a coating to two adjoining edges of a carton or the like.

BACKGROUND OF THE INVENTION For a good number of years, attempts have been made to produce cartons which are sift proof. Cartons are often used to contain a powdered or granulated material which can readily escape from the carton if the carton closure flaps are not properly sealed. A great number of structures have been used in an attempt to provide a perfectly sealed carton. It has been determined that one of the most effective ways is to coat the edges of the flaps after the carton has been filled and closed.

SUMMARY OF THE INVENTION It has been found that a very effective seal can be provided by extruding a coating along the three cut edges of each outermost flap of the end closure. A coating of hot melt adhesive, wax, plastic or other suitable material may be used. This coating is extruded through a suitable right angular nozzle which applies the coating at the juncture between the outermost flap and the next adjacent wall. In view of the fact that the three cutedges of the outermost flap which are to be sealed are in right angular relation, normally the cartons are moved first in one direction where one or two joints are sealed, and then in a direction in right angles to the first direction, so that all of the three edges may be readily coated.

While the sealing may take place at one end only of the carton, if the carton is of the usual paste end type, both ends of the cartons are normally simultaneously coated.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims.

BRIEF DESCRIPTION OF THE DRAWINGS closed carton.

FIG. 5 is a perspective view of one of the extruders.

FIG. 6 is a bottom plan view of the upper plate of the extruder.

FIG. 7 is a top plan view of the bottom plate of the extruder.

3,814,650 Patented June 4, 1974 FIG. 8 is an enlarged detail showing the slots through which the film is extruded.

FIG. 9 is a vertical sectional view indicating the manner in which the extrusion is controlled.

DESCRIPTION OF THE PREFERRED EMBODI- MENT OF THE INVENTION In the following description, and in the drawings, the cartons are shown as having relatively wider parallel front and rear panels, and narrower side panels, as such cartons are prevalent. Obviously, the cartons may be square in cross-section.

In view of the fact that the specific arrangement of the means of applying the coating to the cartons is subject to considerble variation, this portion of this structure is shown diagrammatically. The cartons A which are illustrated in the drawings are generally conventional paste end cartons including a generally rectangular body portion 10, and closure flaps closing the upper and lower ends of the body. In normal practice, the closure flaps at the lower end of the carton are folded and sealed in superimposed relation. The carton is then filled with the product and the top flaps are closed. Subsequent to the normal sealing operation, a sealing coating is applied over the three out edges of the outermost flap so as to prevent sifting from the carton.

In the arrangement illustrated, the body 10 of the carton A is provided with an inner closure flap 11 which is of proper size to close the end of the rectangular body 10. A pair of short fl'aps 12 are shown overlying the full size flap 11. A second full sized flap 13 is hinged to the wall of the body oposite that supporting the flap 11 and between the narrower walls supporting the flaps 12. Alternatively, and as is more usual practice, the short flaps 12 may be folded inwardly of the full size flap 11 rather than out-.

wardly thereof. In any event, one of the full size flaps such as 13 is outermost and is hingedly connected to a Wall along a fold line 14, and is cut along its two parallel side edges as indicated at 15 and along the edge 16 which is parallel to the fold line 14. It is a purpose of the present invention to apply a sealing coating along any or all of the cut edges 15 and 16.

In the present disclosure, as the structure appears in FIG. 2 the forward edges 17 are cut somewhat narrower than the width of the flaps 11 and 13 so as to form a narrow slot forwardly of these edges 17 to accommodate the coating extruded. Somewhat better sealing results have been accomplished by providing this slot and filling it with the extruded coating.

FIG. 3 of the drawings illustrates diagrammatically the general system of operation. As indicated, the cartons in fiat folded form are fed from a hopper 20 into a series of receiving pockets 21 mounted on an elongated endless conveyor 22. As the cartons are fed into the pockets, they are opened up and moved in the direction of the arrow 23 about the conveyor, which directs the cartons beneatha product filling mechanism which is not shown in the drawings. Alternatively, the cartons may be manually filled. During the travel of the cartons about the conveyor 22 the end fiaps of the conveyor are closed and sealed. Obviously, the lower end is sealed before the carton is filled, while the upper end is sealed afterwards.

After the cartons have been closed, they are forced in the direction of the arrow 24 to a conveyor 25 where the cartons travel with the wider walls of the body 10 in parallel relation normal to the direction of. travel. During this time, the cartons pass extruders B which are designed to extrude a coating over the edges 15 of the outer flaps 13. From the conveyor 25, the direction of the cartons is changed by a direction changing means 26 to travel along a right angular conveyor 27 in which the narrower walls 3 of the carton body 10 are parallel and are in right angular relation to the direction of travel. While traveling in this direction, the cartons passed an extruder C which applies a coating over the cut edge 16 of the outermost flap 13.

The extruder and/or applicator such as C is supported by a suitable bracket 30 supported by a frame part 31. In the case of the extruders B, these are arranged on pposite sides of the cartons as indicated in FIG. 3. Normally, the extruders are arranged in pairs including an upper one and a lower one as indicated. The extruders such as B and C are identical and are shown more in detail in FIGS. through 9 of the drawings. Each extruder includes a mounting plate 32 having a valve block 33 secured thereto. An inlet pipe 34 and an outlet pipe 35 are secured to a mounting plate 36 secured to the side of the valve block 33 by bolts 37 or other suitable means. At least one heater element 39 extends through the valve block 33 to maintain the temperature of this block sufliciently high to retain the coating in a molten state. An extruder head 40 is secured to the block 33 and includes a main body portion 41 and a closure plate 42. The body portion and plate are right angularly notched as indicated at 43, and the right angular walls of the notch are mounted so as to be parallel to the walls of the carton on which the coating is extruded.

A solenoid 44 is mounted upon the supporting plate 32 and actuates a plunger 45 connected through a connecting joint 46 to a valve rod 47. As indicated in FIG. 9, the valve rod 47 is slidable in an aperture 49 in the block 33 with which the inlet and outlet communicate. In one extreme position of the valve rod 47, the inlet and outlet pipes 34 and 35 which are shown in dotted outlet in FIG. 9 are connected by suitable means such as the bypass 50 so that the coating will continually recirculate. However, when the valve rod 47 is retracted, a peripheral groove 51 in the valve rod acts to connect the inlet 34 to a passage 52 extending through the valve block 33 and a passage 53 in the body 41 of the the extruder head. As indicated in FIG. 7 of the drawings, the passage 53 leads to a pair of grooves 54 in the upper surface of the extruder head body 41. These grooves 54 lead to a pair or extrusion slots 55 in the extruder head closure plate 42. It is through these slots 55 that the film of coating is extruded toward two adjoining surfaces of the carton A.

The entire purpose of the right angular extrusion is to fill up any crack or crevices between the outermost flap 13 and the closure flaps which it covers. Thus the surfaces of the notch 43 may contact the surfaces of the flap 13 and the walls of the carton. The film which is applied is pref- 4 erably colorless or transparent and a minimum of film remains on the outer exposed surfaces of the carton after application.

The operation of the apparatus is believed obvious from the foregoing disclosure. The solenoid 44 is actuated by suitable detector switches which detect the presence or absence of cartons engaging the extruder head. When the line of filled cartons is continuous as indicated in FIG. 3 of the drawings, the extrusion of the coating can be continuous and the solenoid 44 remains actuated as long as the cartons are in contact with the extruder head. The solenoid is deactivated as soon as the cartons are not present at the various extrusion heads B and C, and the coating is recirculated during such periods.

In accordance with the patent statutes, I have described the principles of construction and operation by my improvement in Sealing Cartons; while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made with the scope of the following Specification and Claims without departing from the spirit of my invention. j

What is claimed is:

1. An extruder head for a carton including an extruder head body, said body being notched to provide two right angularly related surfaces, said head body having a slot at the juncture of said surfaces and substantially right angularly related thereto, and a source of fluid coating connected thereto.

2. The structure of claim 1 and including means for controlling the fiow of fluid coating to said slot.

3. The structure of claim 2 and in which said means for controlling the flow comprises a solenoid actuated valve.

4. The structure of claim 1 and including a conveyor for conveying cartons past said extruder head.

5. The structure of claim 1 and including a second extruder head body similar to the one first described and engaging the carton in opposed relation to the first.

References Cited UNITED STATES PATENTS 1/1945 Straw 93-56 R 9/1958 Von Hofe 93-56 R US. Cl. X.R. 53-284; 93--56 PD; 156-244; 425 461 

